Amnesty International says tactics used by Iraqi forces and their U.S.-led coalition allies in the battle for Mosul violated international humanitarian law and might amount to war crimes.

The London-based rights watchdog said in a July 11 report the Islamic State (IS) militant group had also flagrantly violated humanitarian law by using civilians as human shields.

Iraqi Prime Minister Haidar al-Abadi declared victory in Mosul on July 10, three years after IS seized the city.

A 100,000-strong alliance of Iraqi government units, Kurdish Peshmerga fighters and Shi'ite militias launched the offensive to recapture the city in October 2016, with air and ground support from the U.S.-led international coalition.

Thousands of civilians have been killed and nearly 1 million forced to flee their homes, according to the United Nations.

Amnesty said Iraqi forces and the coalition had carried out a series of unlawful attacks in west Mosul since January.

The top U.S. general in Iraq strongly rejected that coalition strikes violated international law.

"I reject any notion that coalition fires were in any way imprecise, unlawful, or excessively targeted civilians," Lieutenant General Stephen Townsend told a news briefing in Washington.

He added that he believed the fight against IS was the "most precise campaign in the history of warfare."

UN High Commissioner for Human Rights Zeid Ra'ad al-Hussein mentioned in a July 11 statement allegations of rights abuses by Iraqi forces and by individuals taking revenge against captured IS fighters or people accused of supporting them.